Electronic wave functions and optical transitions in (In,Ga)As/GaP quantum dots

Robert, Cédric et al.We study the complex electronic band structure of low In content InGaAs/GaP quantum dots. A supercell extended-basis tight-binding model is used to simulate the electronic and the optical properties of a pure GaAs/GaP quantum dot modeled at the atomic level. Transitions between hole states confined into the dots and several XZ-like electronic states confined by the strain field in the GaP barrier are found to play the main role on the optical properties. Especially, the calculated radiative lifetime for such indirect transitions is in good agreement with the photoluminescence decay time measured in time-resolved photoluminescence in the µs range. Photoluminescence experiments under hydrostatic pressure are also presented. The redshift of the photoluminescence spectrum with pressure is also in good agreement with the nature of the electronic confined states simulated with the tight-binding model.A.R.G. and M.I.A. acknowledge support from the Spanish Ministry of Economy and Competitiveness (MINECO) through Grant No. MAT2009-09480 (PIEZOHM) and Severo Ochoa Excellence Centre Award (No. SEV-2015-0496). M.O.N. acknowledges financial support from the Russian Foundation for Basic Research. This research is supported by “Region Bretagne” through the PONANT project including ´ FEDER funds. This paper is also supported by the OPTOSI Agence Nationale pour la Recherche Project No. 12-BS03- 002-02. This work has been performed using HPC resources of GENCI CINES, TGCC/CCRT, and IDRIS under the allocation No. 2013-[x2013096724].Peer reviewe

TEACHING SENTENCE READING AND RETELLING AND ANSWERING COMPREHENSION QUESTIONS IN A CHILD WITH AUTISM SPECTRUM DISORDER

Children diagnosed with autism spectrum disorder (ASD) frequently show difficulties in the acquisition of multiple repertoires, including verbal behavior. One type of verbal operant behavior is the intraverbal. It involves the emission of a verbal response under the control of a verbal discriminative stimulus, without point-to-point correspondence between them, and the response is maintained by a generalized conditioned reinforcer. This study focused on narrative retelling, which is a skill that comprises intraverbal chains. It is also discussed in the literature that the teaching of this repertoire may improve gains in text comprehension, which also involves the emission of intraverbals, that is, answering questions. Regarding this skill, previous research investigated procedures that may produce the emergence of answering comprehension questions referred as complex ABC intraverbals (related to the stimulus equivalence paradigm) in typically developing children. In general, they were exposed to cycles in which they first read short texts/sentences relating information on three different stimuli (A, B, and C), Thereafter, the children answered several questions representing all possible complex intraverbal relations among the three stimuli from the sentences. Some learners demonstrated the emergence of all complex relations, and further investigations were carried out with the teaching of simpler intraverbal relations of the type of exemplars and categories before the cycles of reading sentences – probing complex ABC intraverbals. Data indicated that more learners showed the emergence of all, or nearly all, complex relations. The present study comprised two systematic replication experiments, with the inclusion of a child with ASD as participant. Both also involved the teaching of sentence reading and retelling through script fading, to analyze the effects of narrative production on the possible emergence of complex intraverbals. In Experiment 1, cycles of teaching sentence reading and retelling – probing ABC intraverbals were administered. As a result, all possible complex relations emerged.  Experiment 2 involved the teaching of simpler intraverbal relations of the type of exemplars and categories before the cycles of teaching sentence reading and retelling – probing ABC intraverbals. All possible complex intraverbal relations also emerged. Data were discussed in the sense that, although positive, it is not clear whether the teaching of sentence retelling and simpler intraverbal relations facilitated the establishment of the complex intraverbals. It is possible that reading the sentences was sufficient. The limitations of the research were presented and discussed, as well as recommendations for future investigations that may more clearly isolate the effects of each manipulated independent variable. Anyway, the current study extended previous investigations by showing that complex intraverbal relations of the ABC type may also be established in a learner diagnosed with ASD.  Article visualizations

Adubação de plantio e doses de nitrogênio em cobertura no milho safrinha

O presente trabalho teve como objetivo avaliar a influência da adubação com formulados na semeadura e doses de nitrogênio em cobertura sobre as características produtivas do milho cultivado na safrinha. O experimento foi conduzido entre os meses de março a junho de 2018, na fazenda da Universidade Estadual de Goiás, Unidade Universitária de Ipameri-GO. O delineamento experimental utilizado foi o de blocos casualizados no esquema fatorial 3 x 5 sendo três formulações de adubos na semeadura (06-22-12; 08-20-15 e 06-22-12 + 2% de carbono orgânico) e cinco doses de N (0, 50, 100, 150 e 200 kg ha-1) em cobertura, com quatro repetições. Determinou-se o teor de nitrogênio foliar, massa fresca e seca de folhas, altura de plantas, diâmetro do colmo, altura de inserção da primeira espiga, comprimento e diâmetro de espigas, massa de mil grãos, massa de plantas por hectare, extração de nitrogênio e produtividade. Diante dos resultados pode-se utilizar indiferentemente os fertilizantes formulados NPK na produção do milho safrinha. As doses de nitrogênio em cobertura apresentam resultados satisfatórios até a dose estimada de 135 kg ha-1 de nitrogênio para o cultivo de milho safrinha.The present study aimed to evaluate the influence of fertilization formulated at planting and doses of nitrogen in topdressing on the yield components of second-crop corn. The experiment was conducted between March and June 2018 on the farm of the State University of Goiás, University Unit of Ipameri-GO. The randomized block design, arranged in a 3 x 5 factorial scheme with four replications, was used. Three fertilizer formulations at planting (06-22-12; 08-20-15 and 06-22-12 + 2% organic carbon) and five doses of N (0, 50, 100, 150 and 200 kg ha-1) in topdressing were evaluated. Leaf nitrogen content, fresh and dry mass of leaves, plant height, stem diameter, first ear insertion height, length and diameter of ears, 1000-grain weight, the mass of plants per hectare, extraction of nitrogen, and grain yield were assessed. Given the results, NPK formulated fertilizers can be used indifferently to grow second-crop corn. Nitrogen doses in topdressing have satisfactory results up to the estimated rate of 135 kg ha-1 for the cultivation of second-crop corn

Physiological potential of mung bean seeds under boron doses and storage periods

Objetivou-se avaliar o potencial fisiológico de sementes de feijão-mungo, em resposta a doses e épocas de aplicação de boro, em diferentes períodos de armazenamento. O delineamento experimental foi inteiramente casualizado em esquema fatorial 3x5x4, com quatro repetições, sendo três estádios fenológicos de aplicação (V0, V9 e R1), cinco doses (0; 1,0; 1,5; 2,0; 2,5 kg ha-1) de boro e quatro períodos de armazenamento (0, 3, 6 e 9 meses), em ambiente não controlado. O potencial fisiológico das sementes foi avaliado pelos testes de germinação, primeira contagem, envelhecimento acelerado, condutividade elétrica, comprimento, massa seca e massa de mil sementes. A dose de 1,0 kg ha-1 de ácido bórico, aplicada no estádio V0, proporciona a obtenção de sementes com alto potencial fisiológico, podendo ser armazenadas durante 6 meses. Aos 9 meses de armazenamento o potencial fisiológico das sementes de feijão-mungo é reduzido e apresenta perda de vigor.The objective was to evaluate the physiological potential of mung bean seeds in response to doses and times of boron application, in different storage periods. The experimental design was completely randomized in a 3x5x4 factorial scheme, with four replications, with three phenological stages of application (V0, V9 and R1), five doses (0; 1.0; 1.5; 2.0; 2.5 kg ha-1) of boron and four storage periods (0, 3, 6 and 9 months) in an uncontrolled environment. The physiological potential of seeds was evaluated by germination tests, first count, accelerated aging, electrical conductivity, length, dry mass and mass of a thousand seeds. The dose of 1.0 kg ha-1 of boric acid, applied at the V0 stage, provides seeds with high physiological potential, which can be stored for 6 months. At 9 months of storage, the physiological potential of mung bean seeds is reduced and shows a loss of vigor

Development of a low-cost prototype: Pitot Tube designed to measure the mass and the volumetric flow rates of fluids

This study aims to develop a low-cost prototype to measure the mass and volumetric flow rate of fluids through the construction of a Pitot Tube. This meter must be able to measure the mass flow rate of air for different pressure values using only the water height level variation. For the development of the prototype, low-cost materials were used, in addition to some necessary tools. These experimental models are a didactic proposal for teaching and learning about the flow of fluids discipline, where it was verified that the experimental values found presented satisfactory results correlated with the theoretical concepts of an ideal fluid present in the literature. Thus, the Bernoulli and Torricelli equations were applied to assess the quality of the measurement method, to facilitate the learning of undergraduate students in the Production Engineering Course through conciliation between theory and practice in the Fluid Mechanics Laboratory discipline classes. Finally, the prototype experiment was exposed to other students at the institutional event called “I Integrar Produção” held by UFRA at the Parauapebas Campus

Usage of Arduino-based Datalogger for thermal comfort variables monitoring

Environmental monitoring is an effective tool to identify problems in anthropic areas, and the emergence of cyber-physical sensors contributes to technological advances in the area. This paper introduces a device based on the Arduino cyber-physical platform to monitor air temperature and relative humidity in real-time with high efficiency. With the relationship between these two environmental variables, it will be possible to calculate the Heat Index (CI), the Temperature and Humidity Index (ITU), the Effective Temperature Index (ET), and the Thermal Discomfort Index (IDT). The Datalogger developed is easily programmable and easy to assemble and presented stable operation and proper functioning

A didactic teaching methodology to assist in the analysis of the economic impact on fuel prices commercialized in the Carajás region.

This research aims to analyze the economic impacts caused by the addition of the third digit after the comma in the prices of fuels commercialized in the Carajás region (Parauapebas, Canaã dos Carajás, Curionópolis e Serra dos Carajás) located in the southeast of Pará State, Brazil, and the professional categories chosen were UBER application drivers, who use gasoline with additives in their vehicles, sales representatives who use motorcycles and regular gasoline for their work and lastly, intercity van cooperative drivers who use regular diesel fuel. The results of the investigation highlighted that there was a total loss of 2,10 BRL, for the three categories of professionals for every 100 liters of fuel consumed, representing an economic impact of approximately 43% for S-10 diesel, 38% for regular gasoline and 19% for gasoline with additives. Furthermore, in the professional categories analyzed, it was observed that the greatest economic impact occurred for the group of inter-municipal van drivers, with an annual cost of 191,52 BRL. Subsequently, App drivers obtained 14,72 BRL of economic implication per year, and finally, with less annual impact, sales representatives with a cost of 2,72 BRL